I have an Entity model with entities of Person and LogPerson. they are identical except that LogPerson has 2 additional fields (LogPersonID, CreateDate). How can I cast a LogPerson into a Person so that the VB.NET code that follows my Linq code doesn't have to try to work with both possible types?

For example:

dim p as person
If useLog then
p = From a In LogPerson Where ID = x
Else
p = From a In Person Where ID = x
End If
textbox1.text = p.firstname

Of course, this is tedious, so if you have a large number of fields or a number of places you have to perform this kind of operation, you might want to look into an auto mapping library, such as AutoMapper.